Abnormal vital signs are poor predictors of mortality associated with pulmonary embolism (PE). Diagnosis of PE and right ventricular (RV) strain with transthoracic echocardiography (TTE) however, has been well documented as a predictor for pending shock and significant in-hospital mortality. One study done by Grifoni S et al, showed that 10% of normotensive patients with PE and RV strain on echo developed PE related shock, and 3% died, whereas normotensive patients without signs of RV strain remained hemodynamically stable.

What are the echocardiographic signs of RV dysfunction secondary to PE?(9472752)

How does thrombus in transit on echo affect Prognosis in PE?(12821255)

A meta-analysis of 1113 patients from the International Cooperative Pulmonary Embolism Registry, all had a baseline echocardiography.

42 patients that had a right heart thrombus on baseline echo.>

Mortality was twice as high for patients with right heart thrombus and PE compared to those without right heart thrombus

Positive Right Heart Thrombus

No Right Heart Thrombus

14 Day Mortality

21%

11%

3 Month Mortality

29%

16%

Conclusion:

Thrombus in transit on echo has a higher mortality than no right heart thrombus.

The difference in mortality was more pronounced in the heparin alone treatment group (vs. lytics or embolectomy)

Treatment

Mortality

No Treatment

100%

Anticoagulation

28.6%

Surgical Embolectomy

23.8%

Thrombolysis

11.3%

In a retrospective study by Rose et al (2002) (11888964) patients with PE and a right heart thrombus had a mortality of 27%. They found these patients did better when treated more aggressively (i.e. thrombolysis or embolectomy)

TAKE HOME POINTS

Point of Care echo is very good for the detection of RV strain

In the setting of suspected PE, RV strain on echo is not sensitive for the prediction of PE but it is more specific.

In the setting of hemodynamic instability the detection of RV strain seems to be very specific for PE

The finding of a right heart thrombus in the setting of PE and RV strain doubles the mortality up to 29%

Echo identified right heart thrombus most likely requires more aggressive treatment such as embolectomy or lytic therapy compared to heparin alone, however this requires further investigation

Great post on the utility of echo in PE. In patients with undifferentiated respiratory distress or impending failure, US is quick way to push yourself in the direction of a diagnosis to help with initiation of management.

The one thing I would caution on is that other studies have found a bit lower +LR for RV strain in the prediction of decompensation. Sanchez et al (http://www.ncbi.nlm.nih.gov/pubmed/18495689) found the + LR to be around 2.4. The truth probably lies somewhere in between but it should be noted that BNP and Troponin are serum markers that can help in the diagnosis of RV strain as well (Tn RR = 8, BNP OR = 6-9)

Hi Anand,
Completely agree. By no means does RV strain = PE, and several of the studies Angela mentioned even stated don’t forget that COPD as well as other diagnoses can cause this finding as well. The LR is probably somewhere between the study you listed and the study Angela listed. I generally get BNP and Troponin if PE is on my differential, because they can be markers of Sub-Massive PE and mean “safe dose lytics” should be considered in the setting of PE. TY for reading and always enjoy your comments.

Thanks for your response and bringing the study you mentioned into the discussion. The high likelihood ratio of 29 stated in Dresden’s study is in fact much higher than previously stated LR.

I think the difference in Dresden’s study compared to the study you mentioned is that the meta analysis included only hemodynamically stable patients in a variety of settings. Dresden’s prospective ED trial included a portion of patients that were already hemodynamically compromised. It ‘s possible this group of patients had a higher pretest probability for PE in the setting of RV strain to begin with compared to other studies that included all comers. This is only presumption however, and as Salim stated the number is probably between the two.